Introduction

GTM32 is a fully self-developed control board by Geeetech for high-performance 3D printers. It keeps Geeetech’s uniformly optimized interface specifications, easy to assemble and with compact layout, high integration and high performance.

GTM32 control board (hereinafter referred to as the control board) adopts the current mainstream high-performance Cortex M3 core chip STM32F103, with its running frequency of up to 72MHz.The control board supports up to 4 stepper motors, namely, XYZ axial motor and an extruder. Users can replace the driving modules, such as A4988 and TMC2100 modules, according to their own needs. Besides, it employs the high performance USB serial chip FT232RL, which enables users to manipulate the control board via USB cable. Its output voltage is 12V.

Features

a. Adopting high-performance Cortex M3 core chip STM32F103, with its running frequency of up to 72MHz.

c. The output voltage of GTM32 control board is 12V. It is characterized by dual power supply design, powering up the hotbed and other electronic components respectively. The current for hotbed is 9A and 7A for other parts.

d. The main circuit adopts in-line fuse, with overcurrent protection and reverse protection. The USB power supply interface has a restorable fuse, with its current at 500mA.

e. The control board features three interfaces for PWM fans.

f. Supporting up to 4 stepper motors, namely, XYZ axial motor and an extruder. The common stepper motor drivers are A4988 and TMC2100.

g. Dual temp sensor input: one for the extruder, the other for the hotbed. 100K thermistor is recommended.

7. XYZ motor: connected with the stepper motor for each axis (the sequence can be found on the back of the board).

8. Fan interface: for PWM fan, PH2.0-2 pin

9. USB interface: Connecting the USB cable with your computer.

Subdivision of Stepper Motor

Use jumper caps to subdivide stepper motor. When jumper cap is plugged, it is ON.

X,Y,Z axis stepper motors

Extruder stepper motors

Detailed settings are as follows.

Subdivision on the basis of A4988 stepper driving module.

Turn ON/OFF Subdivision

MS1 MS2 MS3

OFF OFF OFF full step

ON OFF OFF 1/2 step

OFF ON OFF 1/4 step

ON ON OFF 1/ 8 step

ON ON ON 1/16 step

Development Environment Setting

Interface Connecting and Setting

Note:

Pay attention to the Plus-n-Minus of the power connector, reverse connection can cause irrevocable damages.

A4988 should also be connected to the right port, mismatches and revered directions can cause damage to the main board. Please notice the color of the pins and connect the same colored pins together. If some pins are not color-labelled, pleased follow the picture below.